Linux Driver Verification

In drivers/usb/serial/mos7840.ko:
Group parameter var_group2 is declared under #ifdefs of mos7840_serial_probe,
but after preprocessing it disappeares unlike mos7840_release(var_group2);

        #define SERIAL_LCR_DLAB            ((__u16)(0x0080))
        #define NUM_URBS                        16      
        #define URB_TRANSFER_BUFFER_SIZE        32      
        #ifdef MCSSerialProbe

       /* LDV_COMMENT_END_PREP */
        /* LDV_COMMENT_VAR_DECLARE Variable declaration for function "mos7840_serial_probe" */
        struct usb_serial * var_group2;